Background: The current National Cholesterol Education Program lipoprotein classification system for children and adolescents is recommended for use among 2- to 19-year-olds. This classification system does not take into account gender differences or the natural fluctuations in lipoprotein concentrations that occur with growth and maturation.
Methods and results: Data from the National Health and Nutrition Examination Surveys were used to develop age- and gender-specific thresholds that can be used to denote abnormal levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. Each curve was linked to the adult National Cholesterol Education Program Adult Treatment Panel III lipoprotein thresholds using LMS (Lambda-Mu-Sigma) growth curve regression methods. A series of growth curves and tables are presented that can be used to diagnose high-risk lipoprotein levels in the clinical and research settings. For example, in 1-year increments for males starting at age 12 and extending to age 19 years, the high-risk thresholds for total cholesterol were 6.03, 5.83, 5.70, 5.70, 5.77, 5.88, 6.02, and 6.16 mmol/L. The corresponding high-risk threshold for adults (> or = 20 years) is 6.22 mmol/L.
Conclusions: The present study is the first attempt at developing age- and gender-specific lipoprotein threshold concentrations for adolescents. This new classification system should provide a more accurate diagnosis of high-risk lipoprotein levels and associated cardiovascular risks in adolescents.